Let-back for loom take-ups



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1 f w. H. WAKEFlEL D LET-BACK FOR LOOII nxz-urs Filed Oct. 4, 1923 5 b II wumrfi m-w- "ingrotatesltlie take-up iroll in a steady for;

Patented June 16, 1925.

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a s qnusarrfs, ASS 'GN R T R MBTQN a Know sto u WORKS, or woiaons'rnn,nassacnusnrrs, acoarwganr qa or NAS T LET-BACK'FOB r f ihpplicatibn filed Qctober To all whom time comma,

Be known th t I, W LTER H. WAKE- FIE D, acitizen of the UnitedStatespresid ing at Worcester, in the county or Worcester 1 and State ofMassachusetts, have invented a new and useful Let-Back for Loom ilake-Ups, of which the following is a specification.

This invention relates tolet-bfack mechanismfor takemp motions" and anobject of the invention is to relieve the filling stop motion of the"strain otdisconnecting e e-11p me hani m ro us d i e h n.

a fault in the filli' g occurs.

Take-up 'motions are ordinarily actuated y ome e ul r mar e Par or he 9m nd e i e are: a c n ta t r int r te t motion means of which a trainlofgearr d'i t a h n a faultia e fi es occurs it is necessary for the weftto be withdrawn and unless the take-up roll is moved,

backwardly an amount to compensate the withdrawn weft, athin place willap pe t thall etb ck,

motions are customarily: employed to, permit the take-up roll to havethis retrograde o 1'? 9 se i s, ee sar btere 1 the roll can move backtO' dISQ O Ill'lQQlP gearingconnected therewith from the dr1'v-- in-gmechanism. In the"type' bidet-back motion to which present inventionrelates, the strain of disengaging the take-up motion from its drive hasordinarily been assumed by the filling stop 'motipn, but where thefabric is heavy found that the strain is so great that the stop motioncannotbe relied upon to eflect proper disengagement of the drivingparts? In an application filed by Joseph Wilkinson June 18, 1923, SerialNo. 645,968, there is shown a motion somewhat similar to thev let-backmechanism wherein the several,

parts may be made of relatively light material compared with the work tobe done.

It is a further object of my invention to employ connections between thedisengagmay; j; 4, 152 3. stun i 665,594,

ing mechanism and some adjacent fixed part of; the loom, wherebythefilling stop 'mo{ tion is called upon merely to position theconnections, while the actual strain t' dis engaging the fixed part.

Vith these and other objects in view, which will appear as'thedescription pro ceeds, my inventionresides in the combination andarrangement of partshereinafter setforth and more particularly claimedIn the drawings, wherein one form of my invention is shown, h

I Fig- 1 is a sideelevation of portions of loom having my inventionapplied thereto. Figs; 2 and 3 show certain parts illustrated in Fig. 1in different positions.

Fig. 4- of Fig.1,and

Fig. 5r is vie-W- similar to Fig. {1, but

taken on line 5-5 of'Fig. l and showing motion shaft;- 7

Referring particularly to the drawings, there is shown a lool'n side 10having a fill ing stop motion 11. provided with a fork 12 and tail18flmovable. therewith, A lever la'pi-vote'd at 15 of"'the'loo1n"framehas *The crank shaft 23 has fixed thereon an eccentric 24 surrounded byan eccentric strap 25, by means of which a horizontal reciproeatingmotion is given feed pawl 26. R0- tatab y mounted on a fixed center, asat 27 is a ratchet Wheel 28, the teeth of which are successively engagedby pawl 26 and moved in a clockwise direction as viewed in Fig. 1 whenthe crank shaft 23 is rotating. A hold pawl 29 is pivoted to theframe'at 30 and serves to prevent retrograde movement of ratchet 28 whenthe pawl 26 is moving forwardly.

A stand 31 is secured to the loom side and has pivotally mounted thereonan arm 32' to the outward end of which is pivoted parts is transferredto the is a horizontal section on'line certain connections the filling afoot/L6 positioned for engagement with v let-back pawl 33 which latteris normally in.

contact with one of the teethof the ratchet 28, while the arm 32 isspaced from stop 34 located immediately in front of said arm. The matterthus far described is of the usual construction and no claim is madetherefor.

My improvements consist of an arm 40 fastened to the shaft 20 as shownin Fig. 5 and from the rear end of which depends connector 41. A cam arm42 is loosely mounted upon the shaft 20 between arm 40 and a collar 43fastened to said shaft. For the purpose of raising cam arm 42 I providea toggle joint, one member 44 of which is pivotally connected to a fixedstud 45 and the other member 46 of which is pivotally connected to thelower end of connector 41 as at 47 and also the cam arm 42 at 48. Thecam arm 42 is normally in the position shown in'Fig. 1 with the togglejoint broken and is so positioned as to be out of thepath of the pawl 26when the latter is in its foremost position.

When a fault in the filling occurs, arm 21 will move to the positionshown in Fig. 2 and arm 40 will accordingly be raised, the result ofwhich is to straighten the toggle. As this occurs the cam arm 42 ismoved to the raised position shown in Fig; 2. The parts are so timedthat the pawl 26 moves rearwardly. at the time that arm 19 movesforwardly, the resultof which is that hold pawl 29 is free to be raisedfrom the ratchet wheel 28 when the toggle is straightened. For thepurpose of raising pawl 29 a pin 49 is secured to cam arm 42 and passedunder said holding pawl to raise the latter to the position shown inFig. 2.

By referring to Fig. 1 it is seen that cam 17 is provided with a dwell,th purpose of which is to hold the arm 21 forwardly for an appreciableinterval of time. Dur ing this interval of time, the pawl 26 is movedforwardly and a lateral extension 50 formed thereon is caused to rideupon the upper face of cam arm 42, the effect of this being to disengagethe pawl 26 from ratchet wheel 28. When this takes place the tension ofthe cloth moves the ratchet wheel counterclockwise and the let-back pawl33 moves forwardly until arm 32 is arrested in its motion by stop 34.The

parts will then assume the position shown in Fig. 3. After the fillingfault has been corrected arm 21 and slide 22 are moved to their normalrearward position either by disengaging the tail 13 from the arm 19 orby turning the loom over until foot 16 leaves the dwell 47 on cam 17.

From the foregoing .it will be seen that the cam arm is raised tooperative position with the driving pawl by means of connectors from thefilling stop motion, but thatthe strain and pressure on said cam armincident to the disengagement of the drive pawl and the ratchet wheel istransferred to some fixed part of the loom and not the filling stopmotion.

Having described one form of my invention it will be apparent thatchanges and modifications may be made therein by those skilled in theart and I do not wish to be limited to the specific structuresillustrated, but what I do claim is: 1. In a take-up for looms having afilling stop motion, a reciprocating take-up actuating pawl, a camnormally out of the path of the pawl, a toggle joint interposed betweenthe cam and a fixed point on the loom, and connections between the stopmotion and the toggle to move said cam into the path of the pawl whenthe stop motion operates.

2. In a take-up for looms having a filling stop motion, a reciprocatingtake-u actuating pawl, a cam normally out of the path of the pawl, atoggle joint interposed between the toggle joint and stop motion tostraighten the toggle joint when the stop motion operates to move saidcam in the path of the pawl, said connection resetting the toggle andmoving the cam to inoperative position when the stop motion is restoredto normal running position.

In testimony whereof I have hereunto affixed my signature.

WALTER H. WAKEFIELD.

